diff --git a/quiche/quic/core/quic_connection.cc b/quiche/quic/core/quic_connection.cc
index 8001ceb..de88ae6 100644
--- a/quiche/quic/core/quic_connection.cc
+++ b/quiche/quic/core/quic_connection.cc
@@ -2683,27 +2683,12 @@
                        absl::string_view(packet.data(), packet.length()));
   QUIC_BUG_IF(quic_bug_12714_21, current_packet_data_ != nullptr)
       << "ProcessUdpPacket must not be called while processing a packet.";
-  QuicSocketAddress normalized_self_address = self_address;
-  QuicSocketAddress normalized_peer_address = peer_address;
-  if (normalize_incoming_packets_addresses_) {
-    normalized_self_address = self_address.Normalized();
-    normalized_peer_address = peer_address.Normalized();
-    if (normalized_self_address != self_address) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_normalize_incoming_packets_addresses, 1,
-                                   3);
-    }
-    if (normalized_peer_address != peer_address) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_normalize_incoming_packets_addresses, 2,
-                                   3);
-    }
-  }
   if (debug_visitor_ != nullptr) {
-    debug_visitor_->OnPacketReceived(normalized_self_address,
-                                     normalized_peer_address, packet);
+    debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
   }
-  last_received_packet_info_ = ReceivedPacketInfo(
-      normalized_self_address, normalized_peer_address, packet.receipt_time(),
-      packet.length(), packet.ecn_codepoint());
+  last_received_packet_info_ =
+      ReceivedPacketInfo(self_address, peer_address, packet.receipt_time(),
+                         packet.length(), packet.ecn_codepoint());
   current_packet_data_ = packet.data();
 
   if (!default_path_.self_address.IsInitialized()) {
@@ -2974,17 +2959,12 @@
       last_received_packet_info_.destination_address.IsInitialized() &&
       default_path_.self_address !=
           last_received_packet_info_.destination_address) {
-    bool self_address_changed =
-        default_path_.self_address.port() !=
+    // Allow change between pure IPv4 and equivalent mapped IPv4 address.
+    if (default_path_.self_address.port() !=
             last_received_packet_info_.destination_address.port() ||
         default_path_.self_address.host().Normalized() !=
-            last_received_packet_info_.destination_address.host().Normalized();
-    if (normalize_incoming_packets_addresses_) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_normalize_incoming_packets_addresses, 3,
-                                   3);
-      self_address_changed = true;
-    }
-    if (self_address_changed) {
+            last_received_packet_info_.destination_address.host()
+                .Normalized()) {
       if (!visitor_->AllowSelfAddressChange()) {
         const std::string error_details = absl::StrCat(
             "Self address migration is not supported at the server, current "
diff --git a/quiche/quic/core/quic_connection.h b/quiche/quic/core/quic_connection.h
index 4547ff3..7969a0e 100644
--- a/quiche/quic/core/quic_connection.h
+++ b/quiche/quic/core/quic_connection.h
@@ -2325,9 +2325,6 @@
   // peer. For now, this is only stored for tests.
   QuicEcnCounts
       peer_ack_ecn_counts_[PacketNumberSpace::NUM_PACKET_NUMBER_SPACES];
-
-  const bool normalize_incoming_packets_addresses_ =
-      GetQuicReloadableFlag(quic_normalize_incoming_packets_addresses);
 };
 
 }  // namespace quic
diff --git a/quiche/quic/core/quic_connection_test.cc b/quiche/quic/core/quic_connection_test.cc
index 4a46705..c4fe88f 100644
--- a/quiche/quic/core/quic_connection_test.cc
+++ b/quiche/quic/core/quic_connection_test.cc
@@ -1681,13 +1681,8 @@
   host2.FromString(
       absl::StrCat("::ffff:", connection_.self_address().host().ToString()));
   QuicSocketAddress self_address2(host2, connection_.self_address().port());
-  EXPECT_CALL(visitor_, AllowSelfAddressChange()).Times(0u);
   ProcessFramePacketWithAddresses(MakeCryptoFrame(), self_address2,
                                   kPeerAddress, ENCRYPTION_INITIAL);
-  EXPECT_EQ(GetQuicReloadableFlag(quic_normalize_incoming_packets_addresses)
-                ? self_address1
-                : self_address2,
-            connection_.self_address());
   EXPECT_TRUE(connection_.connected());
   // self_address change back to Ipv4 address.
   ProcessFramePacketWithAddresses(MakeCryptoFrame(), self_address1,
diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index 7fa2a95..d9333b2 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -19,8 +19,6 @@
 QUIC_FLAG(quic_reloadable_flag_quic_no_write_control_frame_upon_connection_close, true)
 // If true, QUIC will default enable MTU discovery at server, with a target of 1450 bytes.
 QUIC_FLAG(quic_reloadable_flag_quic_enable_mtu_discovery_at_server, false)
-// If true, QuicConnection will normalize the packet's source and destination addresses before processing the packet.
-QUIC_FLAG(quic_reloadable_flag_quic_normalize_incoming_packets_addresses, false)
 // If true, QuicGsoBatchWriter will support release time if it is available and the process has the permission to do so.
 QUIC_FLAG(quic_restart_flag_quic_support_release_time_for_gso, false)
 // If true, ack frequency frame can be sent from server to client.